Method for preparing ornithine hydrochloride by separating arginine mother liquor

Abstract

The invention relates to the technical field of biochemical engineering, and provides a method for preparing ornithine hydrochloride by separating arginine mother liquor. The method comprises the following steps: carrying out ion exchange resin separation on the arginine mother liquor, concentrating the obtained ornithine effluent, adjusting the pH value with hydrochloric acid to obtain an ornithine hydrochloride concentrated solution, and carrying out first decoloration, first concentration crystallization, second decoloration and second concentration crystallization to obtain the high-purity ornithine hydrochloride. The method provided by the invention is simple to operate and low in cost, and the purity of the obtained ornithine hydrochloride is 99% or above; according to the method, the mother liquor in the production process of arginine is fully utilized, no extra large amount of raw material input is needed, energy consumption and reagent consumption are low, the production cost of ornithine hydrochloride is remarkably reduced, production benefits are improved, waste emission is reduced, and the method is more environmentally friendly and meets the requirement of sustainable development.

Description

Technical Field

[0001] The present invention relates to the technical field of biochemistry, and particularly relates to a method for separating arginine mother liquor to prepare ornithine hydrochloride. Background Art

[0002] Arginine, as an amino acid that participates in various key physiological processes in organisms, has wide applications in industries such as food, medicine, and health products. Currently, the commonly used method for producing arginine is the fermentation method using Corynebacterium glutamicum.

[0003] During the process of producing arginine using the fermentation method with Corynebacterium glutamicum, ornithine will be produced. During the separation and purification of arginine, arginine mother liquor will be generated. As the number of separation and purification times increases, ornithine gradually accumulates in the arginine mother liquor. Ornithine also has physiological functions and application values that cannot be ignored. In the medical field, it is commonly used to treat hyperammonemia caused by acute and chronic liver diseases and has a positive effect on improving liver function; in the health product field, it can promote the secretion of growth hormone and effectively relieve exercise fatigue, and is favored by fitness enthusiasts and athletes. However, arginine and ornithine have similar structures, and the arginine mother liquor has a high viscosity, making the separation difficult, resulting in low economic utilization efficiency of the arginine mother liquor. Usually, it can only be sold externally, causing waste of resources.

[0004] Currently, methods for efficiently separating ornithine from arginine mother liquor include chromatographic separation and membrane separation, etc. However, the purity of the products obtained by these methods is not high (usually less than 99%), which affects their applications in high-end fields, and the separation cost is relatively high, making them unsuitable for large-scale production. Summary of the Invention

[0005] In view of this, the present invention provides a method for separating arginine mother liquor to prepare ornithine hydrochloride. The method provided by the present invention is simple to operate, has a low production cost, and the obtained ornithine hydrochloride has a high purity.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions: A method for separating arginine mother liquor to prepare ornithine hydrochloride, characterized by comprising the following steps: Subjecting the arginine mother liquor to ion exchange resin separation to obtain an ornithine effluent; the ion exchange resin is WA-2 resin; the flow rate of the arginine mother liquor is 2 - 4 BV / h; Concentrating the ornithine effluent, and then adjusting the pH value to 4.8 - 5 with hydrochloric acid to obtain a concentrated ornithine hydrochloride solution; the vacuum degree of the concentration is -0.085 to -0.1 MPa, and the end refractive index is 55 - 60%; Mix the ornithine hydrochloride concentrate with activated carbon for the first decolorization to obtain a first decolorized solution; the mass of the activated carbon used for the first decolorization is greater than or equal to 5% of the mass of the ornithine hydrochloride concentrate; the temperature of the first decolorization is 55 - 60 °C; Perform first concentration crystallization on the first decolorized solution to obtain crude ornithine hydrochloride; the vacuum degree of the first concentration crystallization is -0.085 to -0.1 MPa, and the final solid content is 75 - 80 wt%; Mix the crude ornithine hydrochloride, water and activated carbon for the second decolorization to obtain a second decolorized solution; the temperature of the second decolorization is 55 - 60 °C; Perform second concentration crystallization on the second decolorized solution to obtain ornithine hydrochloride; the vacuum degree of the second concentration crystallization is -0.085 to -0.1 MPa, and the final solid content is 60 - 65 wt%.

[0007] Preferably, before the ion exchange resin separation, it further includes solid-liquid separation of the arginine mother liquor.

[0008] Preferably, the temperature of the concentration is 60 - 80 °C.

[0009] Preferably, the dosage of the activated carbon for the first decolorization is 5 - 8% of the mass of the ornithine hydrochloride concentrate; the time of the first decolorization is 40 - 60 min.

[0010] Preferably, the temperature of the first concentration crystallization is 55 - 65 °C.

[0011] Preferably, the dosage of the activated carbon for the second decolorization is 3 - 5% of the mass of the crude ornithine hydrochloride.

[0012] Preferably, the mass ratio of the crude ornithine hydrochloride to water is (1 - 2):5; the time of the second decolorization is 40 - 60 min.

[0013] Preferably, the temperature of the second concentration crystallization is 60 - 70 °C.

[0014] Preferably, the concentration of ornithine in the arginine mother liquor is 3 - 5 wt%.

[0015] Preferably, the purity of the ornithine hydrochloride is above 99%.

[0016] The present invention provides a method for preparing ornithine hydrochloride by separating arginine mother liquor, which comprises the following steps: subjecting the arginine mother liquor to ion exchange resin separation to obtain an ornithine effluent; the ion exchange resin is WA-2 resin; the flow rate of the arginine mother liquor is 2-4 BV / h; concentrating the ornithine effluent and then adjusting the pH value to 4.8-5 with hydrochloric acid to obtain a concentrated ornithine hydrochloride solution; the vacuum degree of the concentration is -0.085 to -0.1 MPa, and the end point refractive index is 55-60%; mixing the concentrated ornithine hydrochloride solution and activated carbon for the first decolorization to obtain a first decolorized solution; the mass of the activated carbon used for the first decolorization is greater than or equal to 5% of the mass of the concentrated ornithine hydrochloride solution. The temperature of the first decolorization is 55-60 °C; subjecting the first decolorized solution to the first concentration crystallization to obtain crude ornithine hydrochloride; the vacuum degree of the first concentration crystallization is -0.085 to -0.1 MPa, and the end point solid content is 75-80 wt%; mixing the crude ornithine hydrochloride, water and activated carbon for the second decolorization to obtain a second decolorized solution; the temperature of the second decolorization is 55-60 °C; subjecting the second decolorized solution to the second concentration crystallization to obtain ornithine hydrochloride; the vacuum degree of the second concentration crystallization is -0.085 to -0.1 MPa, and the end point solid content is 60-65 wt%. The present invention uses WA-2 resin, which can separate ornithine from arginine mother liquor, greatly improving the recovery rate of ornithine and reducing resource waste; moreover, by strictly controlling the conditions of steps such as concentration and decolorization, the present invention can effectively remove impurities and obtain a high-purity ornithine hydrochloride product. The present invention makes full use of the mother liquor in the arginine production process, without the need for additional large amounts of raw material input, with less energy consumption and reagent consumption, significantly reducing the production cost of ornithine hydrochloride, improving production efficiency, while reducing waste emissions, being more environmentally friendly, and meeting the requirements of sustainable development. Detailed implementation manners

[0017] The present invention provides a method for preparing ornithine hydrochloride by separating arginine mother liquor, which comprises the following steps: Subjecting the arginine mother liquor to ion exchange resin separation to obtain an ornithine effluent; the ion exchange resin is WA-2 resin; the flow rate of the arginine mother liquor is 2-4 BV / h; Concentrating the ornithine effluent and then adjusting the pH value to 4.8-5 with hydrochloric acid to obtain a concentrated ornithine hydrochloride solution; the vacuum degree of the concentration is -0.085 to -0.1 MPa, and the end point refractive index is 55-60%; Mixing the concentrated ornithine hydrochloride solution and activated carbon for the first decolorization to obtain a first decolorized solution; the mass of the activated carbon used for the first decolorization is greater than or equal to 5% of the mass of the concentrated ornithine hydrochloride solution. The temperature of the first decolorization is 55-60 °C; The first decolorized liquid is subjected to first concentration crystallization to obtain crude ornithine hydrochloride; the vacuum degree of the first concentration crystallization is -0.085 to -0.1 MPa, and the final solid content is 75 to 80 wt%. The crude ornithine hydrochloride, water and activated carbon are mixed for second decolorization to obtain a second decolorized liquid; the temperature of the second decolorization is 55 to 60 °C. The second decolorized liquid is subjected to second concentration crystallization to obtain ornithine hydrochloride; the vacuum degree of the second concentration crystallization is -0.085 to -0.1 MPa, and the final solid content is 60 to 65 wt%.

[0018] In the present invention, the arginine mother liquor is separated by an ion exchange resin to obtain an ornithine effluent. In the present invention, the arginine mother liquor is specifically the third arginine mother liquor, that is, the mother liquor remaining after three separations and purifications of the fermentation broth obtained by the Corynebacterium glutamicum fermentation method; the content of ornithine in the arginine mother liquor is 3 to 5 wt%. Before the ion exchange resin separation, the present invention preferably performs solid-liquid separation on the arginine mother liquor, and the solid-liquid separation method is preferably filtration, and insoluble impurities therein are removed by filtration to obtain a clarified arginine mother liquor.

[0019] In the present invention, the ion exchange resin is WA-2 resin; the present invention has no special requirements on the source of the WA-2 resin, and commercially available products can be used; in the ion exchange resin separation, the flow rate of the arginine mother liquor is 2 to 4 BV / h, specifically it can be 2 BV / h, 2.5 BV / h, 3 BV / h or 4 BV / h; the present invention has no special requirements on the device used for the ion exchange resin separation, and those well-known to those skilled in the art can be used, specifically such as a moving bed, a simulated moving bed or a fluidized bed, etc., and a resin column can also be directly used for separation. In a specific embodiment of the present invention, the arginine mother liquor is preferably passed into a resin column filled with WA-2 resin, and the obtained effluent is collected, which is the ornithine effluent.

[0020] After obtaining the ornithine effluent, the present invention concentrates the ornithine effluent and then adjusts the pH value to 4.8 to 5 with hydrochloric acid to obtain a concentrated ornithine hydrochloride solution. In the present invention, the temperature of the concentration is preferably 60 to 80 °C, specifically it can be 60 °C, 65 °C, 70 °C, 75 °C or 80 °C; the vacuum degree of the concentration is -0.085 to -0.1 MPa, specifically it can be -0.085 MPa, -0.09 MPa, -0.095 MPa or -0.1 MPa; the final refractive index of the concentration is 55 to 60%, specifically it can be 55%, 56%, 57%, 58% or 60%; the concentration is preferably carried out in a rotary evaporator. By controlling the final refractive index of the concentration, the present invention can reduce the volume of the ornithine material, which is beneficial to improving the efficiency of the subsequent carbon addition and decolorization process.

[0021] In the present invention, the hydrochloric acid is preferably concentrated hydrochloric acid (with a concentration of 36 - 38 wt%); ornithine is not easily crystallized. In the present invention, by adding hydrochloric acid, ornithine is converted into ornithine hydrochloride, and then subsequent purification is carried out, which is beneficial to the efficient recovery of ornithine.

[0022] After obtaining the concentrated solution of ornithine hydrochloride, in the present invention, the concentrated solution of ornithine hydrochloride and activated carbon are mixed for the first decolorization to obtain a first decolorized solution. In the present invention, the dosage of activated carbon for the first decolorization is preferably greater than or equal to 5% of the mass of the concentrated solution of ornithine hydrochloride, more preferably 5 - 8% of the mass of the concentrated solution of ornithine hydrochloride, and specifically can be 5%, 6%, 7% or 8%; the activated carbon preferably used for the first decolorization is Yuanli 303 - 05 activated carbon; the temperature for the first decolorization is 55 - 60 °C, and the time is preferably 40 - 60 min, and specifically can be 40 min, 45 min, 50 min, 55 min or 60 min. After the first decolorization is completed, the activated carbon is removed to obtain a first decolorized solution.

[0023] After obtaining the first decolorized solution, in the present invention, the first decolorized solution is subjected to first concentration crystallization to obtain crude ornithine hydrochloride. In the present invention, the temperature for the first concentration crystallization is preferably 55 - 65 °C, and specifically can be 55 °C, 58 °C, 60 °C or 65 °C, the vacuum degree for the first concentration crystallization is - 0.085 - - 0.1 MPa, and specifically can be - 0.085 MPa, - 0.09 MPa, - 0.095 MPa or - 0.1 MPa; the solid content at the end point of the first concentration crystallization is 75 - 80 wt%, and specifically can be 75 wt%, 76 wt%, 77 wt%, 78 wt% or 80 wt%; the first concentration crystallization is preferably carried out in a rotary evaporator; by controlling the conditions of the first concentration crystallization within the above range in the present invention, impurities can be fully removed and the product purity can be improved.

[0024] After the first concentration crystallization is completed, in the present invention, the obtained concentrate is preferably washed with deionized water to obtain crude ornithine hydrochloride.

[0025] After obtaining the crude ornithine hydrochloride, the present invention mixes the crude ornithine hydrochloride, water and activated carbon for secondary decolorization to obtain a secondary decolorized solution. In the present invention, the dosage of the activated carbon for the secondary decolorization is 3-5% of the mass of the crude ornithine hydrochloride, specifically it can be 3%, 3.5%, 4%, 4.5% or 5%; the model of the activated carbon used for the secondary decolorization is the same as that for the primary decolorization, which will not be elaborated here; the mass ratio of the crude ornithine hydrochloride to water is preferably (1-2):5; the temperature of the secondary decolorization is 55-60°C, and the time is preferably 40-60 min, specifically it can be 40 min, 45 min, 50 min, 55 min or 60 min. After the secondary decolorization is completed, the activated carbon is removed to obtain a secondary decolorized solution.

[0026] After obtaining the secondary decolorized solution, the present invention performs secondary concentration crystallization on the secondary decolorized solution to obtain ornithine hydrochloride. In the present invention, the temperature of the secondary concentration crystallization is preferably 60-70°C, specifically it can be 60°C, 65°C or 70°C, and the vacuum degree of the secondary concentration crystallization is -0.085 to -0.1 MPa, specifically it can be -0.085 MPa, -0.09 MPa, -0.095 MPa or -0.1 MPa; the terminal solid content of the secondary concentration crystallization is 60-65 wt%, specifically it can be 60 wt%, 62 wt%, 63 wt%, 64 wt% or 65 wt%; the present invention controls the terminal solid content of the secondary concentration crystallization within the above range, which can fully remove impurities and improve the product purity.

[0027] After the secondary concentration crystallization is completed, the present invention preferably washes the obtained crystals with deionized water to obtain the finished product of ornithine hydrochloride. In the present invention, the purity of the ornithine hydrochloride is above 99%, preferably above 99.3%.

[0028] Next, the technical solutions in the present invention will be clearly and completely described in combination with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] The arginine mother liquor used in the following examples is all the third mother liquor, and the ornithine content is 4.2 wt%. After the third mother liquor is filtered to remove insoluble impurities, the obtained clarified arginine mother liquor is used in the subsequent examples.

[0030] The activated carbon used for the primary decolorization and the secondary decolorization in the following examples is all the commercially available Yuanli 303-05 activated carbon.

[0031] Example 1 5000 mL of the arginine mother liquor was passed into a resin column filled with WA-2 resin at a rate of 2 BV / h to obtain an ornithine effluent. The ornithine effluent was added to a rotary evaporator, and the concentrator was controlled at a concentration temperature of 70 °C and a vacuum of -0.1 MPa and concentrated to a refractive index of 55%. Concentrated hydrochloric acid was added to the concentrated feed solution to adjust the pH value to 5.0 to obtain a concentrated ornithine hydrochloride solution; then activated carbon was added for the first decolorization. The mass of the activated carbon was 5% of the mass of the concentrated ornithine hydrochloride solution. The decolorization temperature was 60 °C and the decolorization time was 40 min. After the decolorization was completed, the activated carbon was removed to obtain the first decolorized solution. The first decolorized solution was subjected to the first concentration crystallization, with the concentration temperature controlled at 55 °C and the vacuum at -0.1 MPa. The final solid content was 75 wt%. After the concentration crystallization was completed, the crystals were washed with deionized water to obtain crude ornithine hydrochloride. The crude ornithine hydrochloride and water were mixed at a weight ratio of 2:5, and then activated carbon with a mass fraction of 5% of the crude ornithine hydrochloride was added for the second decolorization. The decolorization temperature was 60 °C and the decolorization time was 40 min. After the decolorization was completed, the activated carbon was removed to obtain the second decolorized solution. The collected second decolorized solution was subjected to the second concentration crystallization, with the concentration temperature controlled at 60 °C and the vacuum at -0.1 MPa. The final solid content was 65 wt%. After the concentration crystallization was completed, the crystals were washed with deionized water to obtain the finished product of ornithine hydrochloride. Its purity was 99.35% and the recovery rate was 79.4% as detected by liquid chromatography.

[0032] Example 2 5000 mL of arginine mother liquor was passed into a resin column filled with WA-2 resin at a rate of 4 BV / h to obtain an ornithine effluent. The ornithine effluent was added to a rotary evaporator, and the concentration temperature of the evaporator was controlled at 80 °C, and the vacuum degree was -0.085 MPa. It was concentrated to a refractive index of 60%. Concentrated hydrochloric acid was added to the concentrated feed solution to adjust the pH to 5.0 to obtain a concentrated ornithine hydrochloride solution. Activated carbon was added for the first decolorization. The mass of the activated carbon was 8% of the mass of the concentrated ornithine hydrochloride solution. The decolorization temperature was controlled at 60 °C, and the decolorization time was 60 min. After the decolorization was completed, the activated carbon was removed to obtain a first decolorized solution. The collected first decolorized solution was subjected to first concentration crystallization. The concentration temperature was controlled at 65 °C, and the vacuum degree was -0.085 MPa. The final solid content was 80 wt%. After the concentration was completed, the crystals were washed with deionized water to obtain crude ornithine hydrochloride. The crude ornithine hydrochloride and water were mixed at a weight ratio of 1.5:5, and then 8% activated carbon by mass fraction was added for the second decolorization. The decolorization temperature was 60 °C, and the decolorization time was 60 min. After the decolorization was completed, the activated carbon was removed to obtain a second decolorized solution. The collected second decolorized solution was subjected to second concentration crystallization. The concentration temperature was controlled at 60 °C, and the vacuum degree was -0.085 MPa. The final solid content was 60 wt%. After the concentration was completed, the crystals were washed with deionized water to obtain the finished product of ornithine hydrochloride. Its purity was 99.60% and the recovery rate was 78.0% detected by liquid chromatography.

[0033] Example 3 5000 mL of arginine mother liquor was passed into a resin column filled with WA-2 resin at a rate of 3 BV / h to obtain an ornithine effluent. The ornithine effluent was added to a rotary evaporator, and the concentration temperature was controlled at 60 °C, and the vacuum degree was -0.095 MPa. It was concentrated to a refractive index of 58%. Concentrated hydrochloric acid was added to the concentrated feed solution to adjust the pH to 5.0 to obtain a concentrated ornithine hydrochloride solution; then activated carbon was added for the first decolorization. The mass of the activated carbon was 6% of the mass of the concentrated ornithine hydrochloride solution. The decolorization temperature was controlled at 60 °C, and the decolorization time was 50 min. After the decolorization was completed, the activated carbon was removed to obtain a first decolorized solution. The collected first decolorized solution was subjected to first concentration crystallization. The concentration temperature was controlled at 60 °C, and the vacuum degree was -0.095 MPa. The final solid content was 78 wt%. After the concentration was completed, the crystals were washed with deionized water to obtain crude ornithine hydrochloride. The crude ornithine hydrochloride and water were mixed at a weight ratio of 2:5, and then 4% activated carbon by mass fraction was added for the second decolorization. The decolorization temperature was 60 °C, and the decolorization time was 50 min. After the decolorization was completed, the activated carbon was removed to obtain a second decolorized solution. The collected second decolorized solution was subjected to vacuum concentration. The concentration temperature was controlled at 65 °C, and the vacuum degree was -0.095 MPa. The final solid content was 63 wt%. After the concentration was completed, the crystals were washed with deionized water to obtain the finished product of ornithine hydrochloride. Its purity was 99.45% and the recovery rate was 80.3% detected by liquid chromatography.

[0034] Example 4 5000 mL of the arginine mother liquor was passed into a resin column filled with WA-2 resin at a rate of 2.5 BV / h to obtain an ornithine effluent. The ornithine effluent was added to a rotary evaporator, and the concentration temperature was controlled at 80 °C and the vacuum degree was -0.1 MPa. It was concentrated until the refractive index was 56%. Concentrated hydrochloric acid was added to the concentrated feed solution to adjust the pH to 5.0 to obtain a concentrated ornithine hydrochloride solution. Activated carbon was added for decolorization. The mass of the activated carbon was 7% of the mass of the concentrated ornithine hydrochloride solution. The decolorization temperature was controlled at 60 °C and the decolorization time was 55 min. After decolorization was completed, the activated carbon was removed to obtain a first decolorized solution. The first decolorized solution collected was subjected to first concentration crystallization. The concentration temperature was controlled at 62 °C and the vacuum degree was -0.1 MPa. The final solid content was 76 wt%. After concentration was completed, the crystals were washed with deionized water to obtain crude ornithine hydrochloride. The crude ornithine hydrochloride and water were mixed at a weight ratio of 1:5, and then 4.5% by mass of activated carbon was added for second decolorization. The decolorization temperature was 60 °C and the decolorization time was 50 min. After decolorization was completed, the activated carbon was removed to obtain a second decolorized solution. The second decolorized solution collected was subjected to second concentration crystallization. The concentration temperature was controlled at 68 °C and the vacuum degree was -0.1 MPa. The final solid content was 62 wt%. After concentration was completed, the crystals were washed with deionized water to obtain the finished product of ornithine hydrochloride. Its purity was detected by liquid chromatography to be 99.50% and the recovery rate was 77.5%.

[0035] Example 5 5000 mL of the arginine mother liquor was passed into a resin column filled with WA-2 resin at a rate of 3 BV / h to obtain an ornithine effluent. The ornithine effluent was added to a rotary evaporator, and the concentration temperature was controlled at 75 °C and the vacuum degree was -0.09 MPa. It was concentrated to a refractive index of 57%. Concentrated hydrochloric acid was added to the concentrated feed solution to adjust the pH to 4.8 to obtain a concentrated ornithine hydrochloride solution. Activated carbon was added for decolorization. The mass of the activated carbon was 5% of the mass of the concentrated ornithine hydrochloride solution. The decolorization temperature was controlled at 60 °C and the decolorization time was 45 min. After decolorization was completed, the activated carbon was removed to obtain a first decolorized solution. The collected first decolorized solution was subjected to first concentration crystallization. The concentration temperature was controlled at 58 °C and the vacuum degree was -0.09 MPa. The final solid content was 77 wt%. After concentration was completed, the crystals were washed with deionized water to obtain crude ornithine hydrochloride. The crude ornithine hydrochloride and water were mixed at a weight ratio of 1.5:5, and then 5% by mass of activated carbon was added for second decolorization. The decolorization temperature was 60 °C and the decolorization time was 45 min. After decolorization was completed, the activated carbon was removed to obtain a second decolorized solution. The collected second decolorized solution was subjected to second concentration crystallization. The concentration temperature was controlled at 63 °C and the vacuum degree was -0.09 MPa. The final solid content was 64 wt%. After concentration was completed, the crystals were washed with deionized water to obtain the finished product of ornithine hydrochloride. Its purity was detected by liquid chromatography to be 99.40% and the recovery rate was 80.8%.

[0036] Comparative Example 1 Controlling other conditions to be the same as in Example 1, only the final solid content of the second concentration crystallization was controlled at 70%. The purity of the finally obtained finished product of ornithine hydrochloride was 97.82% and the recovery rate was 80.2%.

[0037] Comparative Example 2 Controlling other conditions to be the same as in Example 2, only the final solid content of the first concentration crystallization was controlled at 85%. The purity of the finally obtained finished product of ornithine hydrochloride was 98.20% and the recovery rate was 78.5%. Moreover, during centrifugation, the material was difficult to centrifuge due to too high viscosity.

[0038] Comparative Example 3 Controlling other conditions to be the same as in Example 3, only during the first decolorization, the dosage of activated carbon was reduced to 3% of the mass of the concentrated ornithine hydrochloride solution. The purity of the finally obtained finished product of ornithine hydrochloride was 98.5% and the recovery rate was 81.5%. The impurity content increased significantly, affecting the product quality.

[0039] Comparative Example 4 Controlling other conditions to be the same as in Example 3. Only during the ion resin exchange separation, the flow rate of the arginine mother liquor was increased to 4.0 BV / h. The purity of the finally obtained finished product of ornithine hydrochloride decreased by 20% and the recovery rate was 75.5%, indicating that too fast a flow rate would affect the separation effect.

[0040] Comparative Example 5 Other conditions were controlled to be the same as those in Example 1, except that the WA-2 resin was replaced with the JK-008 type resin. The resulting finished product of ornithine hydrochloride was detected by liquid chromatography, with a purity of 92.5% and a recovery rate of 70.4%, which were significantly lower than the results of Example using the WA-2 resin, indicating that the type of resin has a significant impact on the separation effect.

[0041] Comparative Example 6 Other conditions were controlled to be the same as those in Example 2, except that in the steps of concentrating the ornithine effluent, the first concentration crystallization, and the second concentration crystallization, the vacuum degree was adjusted to -0.05 MPa. The resulting finished product of ornithine hydrochloride had a purity of 98.8% and a recovery rate of 80.6%. Due to the change in the vacuum degree, the concentration efficiency decreased.

[0042] Comparative Example 7 Other conditions were controlled to be the same as those in Example 3, except that in the first decolorization and the second decolorization steps, the decolorization temperature was increased to 70 °C. The resulting finished product of ornithine hydrochloride had a purity of 95.4% and a recovery rate of 76.6%. Due to the too high decolorization temperature, the decolorization effect of activated carbon decreased, and the impurity content of the finished product increased, indicating that too high a decolorization temperature is not conducive to impurity removal.

[0043] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for separating arginine mother liquor to prepare ornithine hydrochloride, characterized in that: The following steps are involved: The arginine mother liquor is separated by ion exchange resin to obtain ornithine effluent; the ion exchange resin is WA-2 resin; the flow rate of the arginine mother liquor is 2-4 BV / h; The ornithine effluent is concentrated, and then the pH value is adjusted to 4.8-5 with hydrochloric acid to obtain an ornithine hydrochloride concentrate; the vacuum degree of the concentration is -0.085-0.1 MPa, and the end point refractive index is 55-60%; The ornithine hydrochloride concentrated solution is mixed with activated carbon for a first decolorization to obtain a first decolorized solution; The mass of the activated carbon used for the first decolorization is greater than or equal to 5% of the mass of the ornithine hydrochloride concentrate; the temperature of the first decolorization is 55-60°C; The first decolorized liquid is subjected to a first concentrated crystallization to obtain a crude product of ornithine hydrochloride; the vacuum degree of the first concentrated crystallization is -0.085 to -0.1 MPa, and the end point solid content is 75 to 80 wt %; The crude ornithine hydrochloride, water and activated carbon are mixed for a second decolorization to obtain a second decolorized solution; the temperature of the second decolorization is 55-60° C.; The second decolorized liquid is subjected to a second concentrated crystallization to obtain ornithine hydrochloride; the vacuum degree of the second concentrated crystallization is -0.085~-0.1MPa, and the end point solid content is 60~65wt%.

2. The method according to claim 1, characterized in that Before the ion exchange resin separation, the arginine mother liquor is subjected to solid-liquid separation.

3. The method according to claim 1, characterized in that The concentration temperature is 60-80°C.

4. The method according to claim 1, characterized in that: The amount of activated carbon used for the first decolorization is 5-8% of the mass of the ornithine hydrochloride concentrated solution; and the time for the first decolorization is 40-60 minutes.

5. The method according to claim 1, characterized in that The temperature of the first concentrated crystallization is 55-65°C.

6. The method according to claim 1, characterized in that The amount of activated carbon used for the second decolorization is 3-5% of the quality of the crude ornithine hydrochloride.

7. The method according to claim 1 or 6, characterized in that: The mass ratio of the crude ornithine hydrochloride to water is (1-2):5; and the second decolorization time is 40-60 min.

8. The method according to claim 1, characterized in that The temperature of the second concentrated crystallization is 60-70°C.

9. The method according to claim 1, characterized in that: The concentration of ornithine in the arginine mother solution is 3-5wt%.

10. The method according to claim 1, characterized in that The purity of the ornithine hydrochloride is above 99%.